High‐Resolution Coccolithophore Morphological Changes in Response to Orbital Forcings During the Early Oligocene

Abstract

Coccolithophores that first evolved in the Late Triassic (Bown, 1987) are one of the most important and widespread types of marine phytoplankton. Their sizes and assemblage compositions are directly affected by ecological and climatic changes (e.g., Faucher et al., 2020;Henderiks et al., 2020;Linnert & Mutterlose, 2013). As calcifying phytoplankton, their cells are covered by calcite scales named coccoliths, whose sizes are shown to be linearly correlated with coccolithophore cell sizes (Henderiks, 2008;Müller et al., 2012). Laboratory culture studies and in situ studies on living species have shown that coccolithophore cellular sizes are directly affected by temperature, nutrients, light intensity, salinity, and CO 2 concentration in sea water (e.g.,